Equatorial Pacific seawater pCO variability since the last glacial period.

The ocean may have played a central role in the atmospheric pCO rise during the last deglaciation. However, evidence on where carbon was exchanged between the ocean and the atmosphere in this period is still lacking, hampering our understanding of global carbon cycle on glacial-interglacial timescales. Here we report a new surface seawater pCO reconstruction for the western equatorial Pacific Ocean based on boron isotope analysis-a seawater pCO proxy-using two species of near-surface dwelling foraminifera from the same marine sediment core. The results indicate that the region remained a modest CO sink throughout the last deglaciation.